Also, if by "b43 is not correct" you mean firmware is missing then try firmware-getB43.tcz extension from repo (maybe already in coreplus.iso) and run it while connected via Ethernet. this extension will install the proprietary firmware for b43 wifi device.

It's better to copy and paste the exact message or attach the dmesg text file

Also better to provide more information like type of install. Like booted from cd, or installed to USB or HDD, etc. etc..If you need b43 firmware then better to install to a USB stick or HDD where you can install the firmware and have persistent storage, this will ensure the firmware is installed on every reboot.